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DATABASE
MBADavid Asirvatham
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Database Model
There four database models: Relational Database Model
Object-Oriented Database Model
Hierarchical Database Model
Network Database Model
the Hierarchical and Network database models arethe oldest and least used
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Relational Database
Most widely used database
it uses a series of two dimensional tables or files
e.g. Partsfile &Customerfile (in earlier example)
each table stores data pertaining to a particular
entity class
An entity class is a concept of things (or people orplaces) that are stored in the database
example of entity class are parts, customers orstudents
an instance (record) is an occurrence of an entityclass
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Relational Database
It is built on a simple concept of representing datain a two-dimensional tables
easy to identify the entity class
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Object-oriented Database
might be tomorrows database (future)
it is based on objects
an entity class in object-oriented database is similar
to the entity class in a relational database
in object-oriented, the object includes orencapsulates both information about a specificentity class and the software instruction
(procedures) to work on the information.
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Object-oriented database
CustomerInformation:
Customer ID
Name
Phone
Address
Procedures:
Add new customer
Get Customer Information
Change Address
Save Customer information
PartsInformation:
Part #
Description
Quantity
Price
Procedures:
Add new part
Get part Information
Update quantity
Save Part information
Object representation
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
OODB
OODB allows you to work with bothdata/information and procedures
object-oriented database management (OOBDMS) isa DBMS software that allows you to develop and
work with OODB
advantages of OODB combines data and procedures thus closer to the way organisations work
reusable (e.g. a Video Rental object may contain Customer object)
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
OODB
CustomerInformation:
Customer ID
Name
Phone
Address
Procedures:
Add new customer
Get Customer Information
Change Address
Save Customer information
Video RentalInformation:
CUSTOMER
VIDEO
Date Rented
Date Returned
Procedures:
Create new Video Rental
Calculate total Price
Get Video Rental Info
Save Video Rental
Related
Objects
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7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 1: Defining Entity Classes
Identity the entity classes e.g. Employee, Department and Job
Identity the primary key e.g. for Employee it is Emp ID
for Department it could be Dept. Code
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 2: Defining Relationships
Entity-Relationship (ER) diagram may be used
There are 7 symbols used in ER: a rectangle to denote an entity class
a diamond to denote a relationship between two entity classes
a line to connect symbols
a 1 to denote a single occurrence
a M to denote multiple occurrence
An o to denote an optional relationship
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 2: Defining Relationship
How to read?
Follow arrow A and B
A :An Employee is assigned to one and must be assigned to one department.
B:A Department may have many employees assigned or may not have
any employee assigned to it.
EMPLOYEE DEPARTMENTM:1
A
B
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 2: Defining Relationship
EMPLOYEE DEPARTMENTM:1
JOBM:M
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 2: Defining Relationship(Normalisation)
After drawing the ER diagram, you will need tonormalise it
Normalisation is a process of assuring that arelational database structure can be implemented as
a series of tables
There are 3 basic rules for normalisation eliminate repeating groups (i.e. M:M relationships)
assure that each field in a relation depends only on the primary key of
that relation
remove all derived fields from the relations
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 2: (Normalisation)
JOBM:MEMPLOYEE
JOBM:1EMPLOYEE-JOBEMPLOYEE 1:M
Primary Key
Emp ID
1345
3758
3899
4571
Primary Key
Emp ID
13453758
3899
4571
Primary Key
Job Code
17
22
2532
Primary Key
Job Code
1722
25
32
Primary Key
Emp ID + Job Code
1345 + 171345 + 25
3758 + 17
3899 + 25
3899 + 32
4571 + 22
4571 + 25
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 3: Defining fields for each Relation
To determine the data that will be in a relation, wemust ask Does this data depend only on theprimary key for this relation?
If yes, then it is in the right relation
Example: Employee (Emp ID, Name, Dept., Dept. Location)
Job (Job Code, Job Name)
Department (Dept., Dept. Location, Number of Employees)
Employee-Job (Emp ID, Job Code, Hours)
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Step 4: Use DDL to create the database
Use the DDL to create the relations
define the data dictionary
set the primary key and properties of each field
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Data Warehouse
A data warehouse is a logical collection ofinformation- gathered from many differentoperational databases - that supports businessanalysis activities and decision-making tasks
it combines information from different databases
gather only the required information for decision-making
require information is defined by the user
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Data Warehouse
most data warehouses are multidimensionaldatabases - they contain layers of columns and rows(this is called hybercube)
Product
3
Penang
Ipoh
KL
Melaka
JB
Product
1
Product
2
Product
4
Product
5
Year
Credit
What percentage of the total sales for
product 3 in Ipoh were credit sales?
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Data warehouse
Data warehouse also has a data dictionary
the data dictionary maintains: logical structure of the information
origin (source database)
methods (e.g. total, count, average, std deviation, etc)
Data warehouse supports online analyticalprocessing most database support online transaction processing
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuUniversity of ChoiceDavid Asirvatham
Database Systems
Data Mining Tools
Data mining tools are software tools used to query
information in a data warehouse
it supports online analytical processing
Data mining includes:
Query-and-Reporting Tools
Intelligent Agents
Multidimensional Analysis Tools
DATA
WAREHOUSE
DATA
WAREHOUSE
ENGINE
Query-and-Reporting Tools
Intelligent Agents
Multidimensional Analysis Tools
7/31/2019 Lesson 2 Database
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TITLE
CONTENT
msuU f hDavid Asirvatham
Database Systems
Data Mining Tools
Query-and-Reporting Tools use similar tools as QBE, SQL and report generation tools
Intelligent Agents uses artificial intelligence tools such as neural networks and fuzzy logic to
form the basis of information discovery e.g. Data/Logic is used by some Wall Street analyst
e.g. Data Engine
Multidimensional Analysis Tools
is a slice-and-dice technique allows a user to view multidimensional information
e.g. Forest & Trees (North Memorial Medical Centre which has 10,000daily patient records)